Gun magazines will soon feature Brownells’ new line of Retro AR-15 rifles. One of the biggest firearms vendors and gunsmith suppliers, Brownells recently released its own replica of the CAR-15 Commando, or XM177E2 as designated by the US military. In this article, we delve into the origins of the XM177E2, to show how far the AR-15 rifle has evolved from one of the Vietnam War-era ancestors of the AR-15 and M4 families.

The CAR-15

In early 1965, Colt endeavored to market its M16 rifle as a complete, Modular Weapons System for the US Military. Designated by Colt as the CAR-15 or Colt Automatic Rifle-15 family, it was envisioned that by switching various components, the M16 could be reconfigured for different roles like assault rifle, belt-fed LMG, carbine, SMG, SAW and even as a “survival rifle”. Unfortunately, the US Military chose only the Rifle and Commando platforms, prompting Colt to abandon their plans of marketing a complete “family” of 15 different firearms. The “CAR-15 Rifle” was known to most users as the Colt M-16, and similarly used to denote the Colt SMG and Commando variants. Since then, the name “CAR-15” has been used to describe M-16 rifles, despite never being officially named as such.

The CAR-15 Carbine

After the success of the M16, the US Military wanted a “submachinegun” version–one that vehicle crews, K-9 and special forces units could use in smaller spaces, and in situations requiring a more maneuverable weapon to fire from the shoulder or hip. The first model produced was the Model 607 CAR-15 SMG. Although an SMG should use a pistol caliber, but Colt and other weapons manufacturers used this designation for shorter models, and to differentiate them from full-length rifles. Initially, only 50 CAR-15 rifles were made, with most issued to Navy SEALs, K-9 handlers and special forces units.

The Colt Commando

The first Model 607 CAR-15 SMG was a failure, so in 1966, Colt engineer Rob Roy made changes to the CAR-15; first, the tubular aluminum buttstock was simplified to have only two positions. The fragile triangular handguards were replaced with more durable cylindrical handguards. A longer combo flash and sound suppressor (called a “moderator”) was installed to diminish sound and muzzle flash, as well as mitigate weight and reliability issues. This “improved” model was the Model 610 Commando, or XM177. The US Air Force adopted this model and designated it the GAU-5A/A (“Gun, Aircraft, Unit”).

The XM177E2

From Model 610, more versions followed, until settling on “Model 629”, or XM177E2. In April 1967, 510 units were issued to the Military Assistance Corps Vietnam – Studies and Observation Group (MACV-SOG). Colt intended to include several 30-round magazines with each rifle, but a mag that fit into the XM177E2’s magazine well and fed reliably couldn’t be produced in time; this forced SOG members to buy higher-capacity magazines from the US civilian market on their own. Production of the XM177E2 ceased in 1970.

Brownells XBRN177E2 Carbine

This is a faithful reproduction of the Vietnam War-era carbine of the same iconic rifle used by K-9, vehicle crews, and special forces units. It’s an almost exact recreation of the XM177E2, save for the non-functioning “Auto” setting on the Safety. Brownells’ reproduction is semiauto-only to comply with state and federal gun laws. Available in black or gray anodized finish, Brownells’ XBRN177E2 similarly features the non-detachable carrying handle with rear sight, A1 front sight, M16A1 pistol grip, M16A1 upper and lower receiver, teardrop-shaped forward assist, rounded handguards, two-position extendable stock, the (dummy) barrel lug for rifle grenades, and 4.25-inch flash/sound moderator. Included are a 20-round magazine, GI Operations Manual and Chamber Flag. Like the original, the barrel has a 1-in-12 twist. All the rifle’s components are brand-new. The rifle is deemed BATFE regulation-friendly, since the barrel is pinned and the muzzle device is welded on.


By Ramon Berenguer
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